If you went shopping for toys, you'd notice that there isn't anything that is targeted for babies less than 6 months old. The reason is that babies don't really use toys at that age. His best toy is going to be you-your hands, your face...
Rattles are good. Anything for tummy time to encourage rolling over.
My daughter liked stuffed animals, anything that sang, and of course, pulling my hair and grabbing my face. She also loved when I put on music and danced around the house with her in my arms.
I have been home with her since her birth as well. She is 1 and 1/2 now.